Oxygen-free radicals, more generally known as reactive oxygen species (ROS) along with reactive nitrogen species (RNS) are well recognised for playing a dual role as both deleterious and beneficial species. The “two-faced” character of ROS is substantiated by growing body of evidence that ROS within cells act as secondary messengers in intracellular signalling cascades, which induce and maintain the oncogenic phenotype of cancer cells, however, ROS can also induce cellular senescence and apoptosis and can therefore function as anti-tumourigenic species. The cumulative production of ROS/RNS through either endogenous or exogenous insults is termed oxidative stress and is common for many types of cancer cell that are linked with altered redox regulation of cellular signalling pathways. Oxidative stress induces a cellular redox imbalance which has been found to be present in various cancer cells compared with normal cells; the redox imbalance thus may be related to oncogenic stimulation. DNA mutation is a critical step in carcinogenesis and elevated levels of oxidative DNA lesions (8-OH-G) have been noted in various tumours, strongly implicating such damage in the etiology of cancer. It appears that the DNA damage is predominantly linked with the initiation process. This review examines the evidence for involvement of the oxidative stress in the carcinogenesis process. Attention is focused on structural, chemical and biochemical aspects of free radicals, the endogenous and exogenous sources of their generation, the metal (iron, copper, chromium, cobalt, vanadium, cadmium, arsenic, nickel)-mediated formation of free radicals (e.g. Fenton chemistry), the DNA damage (both mitochondrial and nuclear), the damage to lipids and proteins by free radicals, the phenomenon of oxidative stress, cancer and the redox environment of a cell, the mechanisms of carcinogenesis and the role of signalling cascades by ROS; in particular, ROS activation of AP-1 (activator protein) and NF-κB (nuclear factor kappa B) signal transduction pathways, which in turn lead to the transcription of genes involved in cell growth regulatory pathways. The role of enzymatic (superoxide dismutase (Cu, Zn-SOD, Mn-SOD), catalase, glutathione peroxidase) and non-enzymatic antioxidants (Vitamin C, Vitamin E, carotenoids, thiol antioxidants (glutathione, thioredoxin and lipoic acid), flavonoids, selenium and others) in the process of carcinogenesis as well as the antioxidant interactions with various regulatory factors, including Ref-1, NF-κB, AP-1 are also reviewed.

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As with any procedure, there could be pain or other substantial risks involved. These concerns should be discussed with your health care provider prior to any treatment so that you have proper informed consent and understand that there are no guarantees to healing.

THE INFORMATION IN THIS WEBSITE IS OFFERED FOR GENERAL EDUCATIONAL PURPOSES ONLY AND DOES NOT IMPLY OR GIVE MEDICAL ADVICE. No Doctor/Patient relationship shall be deemed to have arisen simply by reading the information contained on these pages, and you should consult with your personal physician/care giver regarding your medical treatment before undergoing any sort of treatment or therapy.

* Legal Disclaimer: Chelation and Hyperbaric Therapy, Stem Cell Therapy, and other treatments and modalities mentioned or referred to in this web site are medical techniques that may or may not be considered “mainstream”. As with any medical treatment, results will vary among individuals, and there is no implication or guarantee that you will heal or achieve the same outcome as patients herein.

As with any procedure, there could be pain or other substantial risks involved. These concerns should be discussed with your health care provider prior to any treatment so that you have proper informed consent and understand that there are no guarantees to healing.

THE INFORMATION IN THIS WEBSITE IS OFFERED FOR GENERAL EDUCATIONAL PURPOSES ONLY AND DOES NOT IMPLY OR GIVE MEDICAL ADVICE. No Doctor/Patient relationship shall be deemed to have arisen simply by reading the information contained on these pages, and you should consult with your personal physician/care giver regarding your medical treatment before undergoing any sort of treatment or therapy.